Measurement from Feynman diagram

[wasi-uz-zaman]

TL;DR

different calculations from Feynman diagram

hi, can anyone please give me the list of measurement we can do ON Feynman diagram?
Like , branching ratio, cross-section etc

 

[Orodruin]

Those are not measurements you do on Feynman diagrams. Feynman diagrams are not for measuring things, they are graphical representations of terms of a mathematical expression. In order to conclude this from them you need to do the math.